Dangerous connections?

Hello,
A few months ago i posted a question about connecting a bit of equipment to the mains power utility, and the practice of passing 20 Amperes down the
power plant return (no neutral) in a 3-phase supply. I also dislike the practice of shorting the power plant return (PE) to the neutral (N) in the user equipment.
I have since been told to keep my mouth closed. This is the way we do it, although still I refuse to put what I call "dangerous information" into the BrE installation instruction card for installers in my workshop.
In this group i was asked repeatedly for the equipment and manufacturer, which i refused to deliver. Ok, well here it is. Scans from the manual and the source material. i put it all on an site:
http://arthur-stoggett.angelfire.com /
Am i right? Are some of these power connections dangerous?
Country = England (Bedford) where British and EU laws prevail.
Arthur
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On 8/1/07 1:14 AM, in article f8pfch$f15$ snipped-for-privacy@news.al.sw.ericsson.se, "Arthur"

I think we (Brits and Americans) are still being divided by the same language. I have trouble understanding just what it is that you are trying to get across. I presume PE stands for Protective Earth which corresponds to our Protective Ground. I can see that a balanced load does not need a neutral connection but you imply that imbalance is present.
I think you are doing the right thing. You will be able to sleep more easily at night. We do have a saying around here: No good deed goes unpunished.
I only looked at the first diagram.
Bill
--
Iraq: About three Virginia Techs a month


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Drg 4,5,6,11 & 12 seem ok but more info would be helpfull
If in doubt get a good sparks on the case.
Gavin Northampton
wrote:

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I included both good and bad drawings - all of them.
Protective Earth = PE = PG = Protective Ground = Power plant return safety earth = yellow/green wire in the power cable.
N = Neutral L1, L2 and L3 = the three live phases.
Now take a look at the last drawing that instructs me to connect all 3 phases together to form a single-phase equipment. the PE and N are also strapped together.
These two connections are then connected to the power companies distribution box, and the two wires are connected between PE and L1.
A
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On Wed, 01 Aug 2007 11:42:20 -0700, Salmon Egg

The NEC is pretty unambigous about this one
Grounded Conductor. A system or circuit conductor that is intentionally grounded.
The very few excpetions that allow this to be copnnected to the "grounding" conductors will all be gone in 2008. It is basically not allowed unless the connection is made on the ground bus in the panel serving a building ... until 2008 when that goes away for sub-panels* (*panels downstream from the service disconnect)..
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On 8/1/07 5:35 PM, in article snipped-for-privacy@4ax.com,

<snip>
In this case it took a few seconds to realize that PE stood for protective earth.
Bill
--
Iraq: About three Virginia Techs a month


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There isn't enough info in those docs to know how the load is connected to the terminals. Also, I can't see if the terminal block is before or after the supplier's cutout -- is the supplier's main cutout in the cabinet?
In the UK, there is a common supply system called TN-C-S (or Protective Multiple Earthing) where the protective earth and neutral are shared in the supply network in a PEN (Protective Earth and Neutral) conductor. These are separated at the supplier's cutout though. However, if the supplier's cutout is in the cabinet, then there would seem to be no point in separating them at that point, although I'm not familiar with supplies to street furniture.
--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]
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Take a look at picture #3. The cable from the power companies distribution box is only two wires:
- Protective earth/ground - One live phase
The connection block is in the user equipment, and the power cables comes from the power companies distribution box.

In a system where the power provider has both protective earth and neutral at the point of delivery, the user equipment may not later bond the PE and N together, if they are provided as seperate conductors. It matters not what the power service provider does to provide these two conductors.
A
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The bit of wire comes from the power companies junction box. The charts explain where to connect the wires. The terminal block is inside the user equipment.
The last drawing for example, shows the power company have provided only two wres: - PE (PG), Ground, Earth, safety earth, green/yellow wire. - Live, single phase, 230v AC
The drawing shows that inside the equipment we are expected to connect together the protective earth/ground (cabinet chassis) and the power neutral. In this configuration if the PE (earth/ground wire) becomes open-circuit, then the metal cabinet in the high-street will have 230v AC live cabinet that passers-by can touch. In normal operation one can expect 20 to 40 Amperes of current down the protectibe earth/ground wire in this configuration.
Other configurations show that in this user equipment we have to short together the power companies protective earth/ground and the neutral conductors, which is also illegal by both EU ans UK regulations.
I can accept the three phases and PE (PG) when configured phase-to-phase, BUT when each phase is returned throgh the power supply companies protective earth/ground wire then my teeth start to move about, and the hairs on the back of my neck stand up: I don't like putting current down the protective earth wire, ESPECIALLY on a bit of equipment that is to stand on the high street with the general public leaning against it.
The ONLY configuration I have installed with equipment is L1, L2, L3, N, and PE as five seperate conductors, all provided by the power company.
Arthur
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